Electric attachment plug receptacle



May3l, 1938. -c.w. ABBOTT 7 5 ELECTRIC ATTACHMENT PLUG RECEPTACLE Filed Dec. 15, 1934 46 ......nulfl l6 INVENTOR CHARLES W ABBOTT BY HIS ATTORNEYS Patented May 31, 1938v ELECTRIC ATTACHMENT PLUG REGEPT ACLE I Charles W. Abbott, Larchmont, N. Y. Application December 15, 1934, Serial No. 757,717

7Claims.

This invention relates to electric attachment plug receptacles. More particularly it relates to attachment plug receptacles for use with surface wiring where both the electric wiring conduit and the receptacle are secured to the outside of the wall in a room of a dwelling or other structure.

My receptacle is particularly adapted for use with the wiring system described in my copending application Serial No. 571,962, patented December 18, 1934, No. 1,984,355.

It is an object of my invention to provide an attachment plug receptacle for mounting upon the surface of a wall in such a position for example as adjacent the base board, which receptacle may be inverted so that either side of it may be adjacent the base board and still permit the wiring conduit to enter directly into the receptacle without deviation from its rectilinear direction.

Another object of my invention is to provide a polarized electric attachment plug receptacle for surface wiring, which can be used adjacent a base board and which may have either the grounded or the live side adjacent the base board depending upon whether the grounded line is uppermost or not in the conduit.

Another object of my invention is to provide a receptacle of the above type which may be economically constructed of few parts and easily and quickly assembled and attached to a wall.

Another object of my invention is to provide a receptacle of the above type which when connected with a wiring conduit will completely enclose all current carrying parts.

Other objects and advantages of my invention will become apparent as it is described in connection with the accompanying drawing.

In the drawing:-

Figure 1 is a plan view oi a receptacle constructed according to the principles of my invention shown in position adjacent a base board. A portion of the cover of my receptacle is broken away for the purpose of illustration.

Figure 2 is a plan view of the base showing the construction and positioning of, the parts. This view is on a slightly larger scale than Figure 1.

Figure 3 is an end view vof the construction shown in Figure 1. v Figure 4 is a side elevation view of my receptacle with the cover in section taken-along the line H of Figure 1. v

Referring to the drawingja' wall II with a base board l2 attached to it adjacent the floor, has

attached to it an electric wiring conduit "of the type illustrated in my copending application Berial No. 571,962 now Patent 1,984,355. This type of conduit as explained in my aforementioned copending application has the advantage that it is more readily adapted to turn corners than conduits for surface wiring which have been used heretofore. One reason for this, as described in my copending application is the fact that the wires l5 and I! lie loosely within the conduit although they are isolated by the central rib Ma, and are not required to expand and contract in the same way as the flexible rubber casing of the conduit at corners. Notwithstanding the adaptability of this type of conduit to make curves when necessary, it is desirable insofar as possible both from the standpoint of appearance and from ease of installation that the conduit be continued in a straight line and that curves be avoided. This is particularly true where the conduit is positioned to run parallel and slightly above or adjacent to the floor molding or base board of a room.

The base ii of my receptacle preferably comprises a slab of insulating material with a flat rear face adapted to lie against the wall III. This base is preferably rectangular in plan and has one or more lugs ll, 20 on opposite sides of the base adapted to fit into recesses formed in the side walls 0! a cover 24. The lugs II are staggered with relation to the lugs 20 so that the cover 2i may be fitted over the base It in one way only and thus is incapable of reversal with respect to the base. This is imperative in a polarized device as hereinafter explained.

The base it .has formed upon it at its central portion a. longitudinally extending spine 20 to separate and insulate two identical metallic members which are secured to the base on opposite sides of the spine and comprise contact portions 2!, 20 and wire terminal portions 80, ll. These metallic members may be stamped from sheet metal. The metallic members are secured to the base by means of oppositely directed arms 32 extending laterally from the wire terminal portions 30, ll and bent down into recesses 34 formed in the base It at the sides of the wire terminal portions. The contact portions 28, 20 of the metallic members are bent up at right angles to the wire terminal portions and have contact fingers 28, 28' at their ends forengagement with the prongs of a conventional attachment plug cap in the usual manner. Wire binding or terminal screws are turned into threaded apertures in the wire terminal portions l0, 3! to hold the conductors or wires II and ll of the conduit IA. To keep these wires from slipping out from beneath the heads joined to the end walls by a stepped formation 24f, although the top could be connected directly to the end walls.

Each end wall comprises a pair of spaced weakened sections, the outline of one ofthese sections being shown at 246. These sections are made mechanically weak so as to be capable of destruction upon the application of a small amount of force which may be applied by the use of a screw driver or a pair. of pliers or other handy tool in the equipment of an electrician. The portions of the wall around these sections of reduced strength are considerably stronger than the sections so that the wall itself is not destroyed by the re moval of the weak section. Preferably the area and shape of the weak sections are substantially identical with the cross section of the wiring conduit [4 with which the receptacle is designed to be used. Therefore upon the breaking away of a. section the end of a conduit may be entered beneath the cover. In length the cover is slightly longer than the length oi the base as shown in Figure 1, in order that the conduit may enter beneath the protection of the cover before the bare wires of the conductors l5 and I! are exposed for a. connection with the terminal screws 01' the metallic members. Because of the fact that the conductors l5 and ll. are bare it is necessary for them to be separated immediately upon their exit from the protection of the outside covering of the conduit H. For thispurpose a pair of posts 40, 42 are formed upon the base at its ends in position directly opposite the sections of reduced strength. Thus when the conduit I 4 is entered beneath the cover as-shown in Figures 1 and 3 with its end abutting the edge of the base, the post 42 will in'effect form a continuation of the wire-isolating rib I la of the conduit.

In some localities it is required-by the authorities that one wire of the circuit shall be grounded and that electric wiring devices shall have the terminals to which the grounded wire is to be connected differ in appearance from the other terminal of the electric wiring device. This difference in appearance is generally accomplished by tinning one of the terminals and leaving the other with its natural copper'or brass appearance. In the present case the lowermetallic member (29, 38) is the one designated for connection to the ground and conductor I1 is the grounded conductor.

ment plug caps have one prong larger than the other. In' order that only that prong (the larger of the two) of an attachment plug cap which is designated for connection to ground, shall be connectible to the grounded metallic member, special precautions must be taken in forming the cover, as will now be described.

The top of the cover 24 is provided with two pairs of apertures 44 and 46 positioned over the contact fingers 28', 29' respectively. The.aperture 46 is larger than the aperture 44 in order that the larger or ground prong of the conventional polarized attachment plug cap may fit into aperture 46 but not into aperture 44 and hence the cap may not be connected with the receptacle It will be recalled by those skilled- 'in the art that conventional polarized attachwhile in reversed position. In order that the cover may be placed on the base only in the position with the large apertures over the grounded contacts 29', pairs of lugs l8 and 20 staggered with relation to each other project from opposite sides of the base and fit into recesses in the sides of the cover.

As before mentioned, the lower contacts 29' and conductor l! are grounded. Hence, in connecting the receptacle to the conduit the lower weak section is broken away and the side of the receptacle is placed adjacent the top of the molding and is secured in that position with the end of the conduit entering under the cover up to the end of the base. At that point the covering for the wires of the conduit is removed and the wires are led to the terminals 30, 3! as follows. The wire 65 is led above the post 42 around the end of the spine 26 to the terminal 30, and the grounded wire I1 is led below the post 42 directly to terminal 39.

If, by chance, the ground wire should be uppermost in the conduit the receptacle would be reversed, putting the contacts 28 and tenminal 30 nearest the base board and the ground terminal 3| and contacts 29 uppermost. Then the section 24c and its opposite at the other end of the cover would be nearest the molding and would be broken away for the conduits entrance.

In this case the wires are led on opposite sides of posts 40 instead of posts 42.

The value and utility of the construction and positioning of the posts 40, 42 and the pair of weakened sections in each end of the receptacle becomes apparent upon consideration of the fact that the wires l5 and I] in the conduit are bare and must not be crossed but must be kept separate from the moment of their exit from the protection of the. insulation of the conduit. The construction just mentioned gives a flexibility of use to the receptacle that is not possible with prior constructions.

For securing the base It to the wall the spine 26 is enlarged at its ends and pierced as at 46 for the accommodation of wood screws. Also within the enlarged ends of the spine are other piercings 48 which are internally threaded and in which are received machine screws coming through apertures in the cover to hold the cover 7 on the base.

From the foregoing it will be apparent that I have constructed a receptacle for mounting adjacent a base board, parallel to which an electric conduit runs, which receptacle permits the entryv of the conduit therein without the necessity of the conduit being bent in any way to make such entry and without the necessity of deviation of the conduit from its rectilinear direction or cross- .ing of the conduit wires. It will also be apparent that the foregoing is accomplished in spite of the fact that the receptacle is adapted for use in a polarized circuit. It will furthermore be apparent that my receptacle covers'all current carrying parts at all points and keeps them shielded from accidental contact which might cause a person to receive a shock or a short circuit to Many modifications within the scope of my invention will occur to those skilled in the art.

Therefore I do not limit myself to the exact conmembers on opposite sides of said spine, said metallic members having contact portions and terminal portions, a pair of spaced posts at each end of said base, a cover fitting over said base and having apertures over said contact portions, said apertures being of difierent configuration whereby the receptacle is polarized, said cover having flat sides adapted to lie along a base board, each end wall of said cover being provided with a pair of spaced sections of reduced strength any one of which may be removed for the entrance of a surface wiring conduit running parallel to the base board whereby the conduit may enter directly into said cover without deviation from its rectilinear direction irrespective of which side of the receptacle is uppermost.

2. In an attachment plug receptacle for surface wiring, an insulating base having a longitudinally extending central spine, metallic members on opposite sides of said spine, said metallic members having contact portions and terminal portions, a cover fitting over said base and apertured over said contact portions, said cover having flat sides adapted to lie along a base board,

each end wall of said cover being provided with a pair of spaced sections of reduced. strength any one of which may be removed for the entrance of a surface wiring conduit running parallel to the base board, a pair of posts at each end of said base, a post being opposite each of said sections whereby the wires of a surface wiring conduit are separated within the receptacle and the conduit may enter directly into said cover without deviation from its rectilinear direction irrespective of which side of the receptacle is uppermost.

3. In an attachment plug receptacle for surface wiring, an insulating base, a cover for said base, contacts within said receptacle accessible through apertures in said cover, said cover having flat sides adapted to lie along a base board, each end wall of said cover being provided with a pair of spaced sections of reduced strength any of which may be removed for the entrance of a surface wiring conduit, a pair of posts at each end of said base, a post being opposite each of said sections, whereby'the wires of the conduit are separated within the receptacle irrespective of which section the conduit enters.

4. In an attachment plug receptacle for surface wiring, an insulating base, contact members in said receptacle for engagement by the prongs of an attachment plug, a cover of greater length than said base, each end wall of said cover having spaced sections of reduced strength any of which sections may be removed for the entrance of a surface wiring conduit running parallel to a molding, said cover having flat sides adapted to lie along the molding, whereby upon removal of the one of said sections nearest the molding the conduit may enter into said cover in unbroken condition, without deviation from its rectilinear direction, and posts on said base at each end opposite said sections for separating the wires of said conductor within said receptacle.

5. In a receptacle for a surface wiring system, a base of insulating material, contacts thereon for engagement by the prongs of an attachment plug cap, wire terminal means on said contacts, a cover for said base having a length greater than the base, a pair of weakened sections removable for the entrance of a surface wiring conduit of the type having a central rib separating parallel wires, said base having posts opposite each of said weakened sections in position to form a continuation of the central rib of the conduit when the end of the conduit within the cover abuts the end of the base.

6. In a receptacle for a surfacewiring system, a base of insulating material, contacts thereon for engagement by the prongs of an attachment plug cap, wire terminal means on said contacts, a cover for said base, means at each end of the cover removable to form an entrance passage for of said conduit has entered said cover and is in abutment with said base.

7'. In an attachment plug receptacle for surface mounting, a one-piece base of insulating material adapted to be attached to a wall, a

one-piece hollow insulating cover for said base constructed and arranged to conceal and protect all current carrying parts on said base, said base having a central longitudinally extending rib, like formed metallic members on opposite sides of said rib and shielded from each other by said I rib, said metallic members each having a plurality of contact portions and a wire terminal portion, binding screws in said terminal portions positioned for manipulation from the front of the base, said cover having slots in register with said contact portions, and sections of reduced strength in each end of said cover adapted to be broken away to permit entrance of a conductor. CHARLES W. ABBOTT. 

